Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 227 PM EST Fri Nov 29 2024 Valid 00Z Sat Nov 30 2024 - 00Z Mon Dec 02 2024 ...Arctic blast brings coldest air since last Winter to much of the eastern half of the country... ...Heavy Lake effect snow continues into the weekend across the Great Lakes... An Arctic airmass has moved southward across the northern Plains/Midwest into the South/East Coast and is expected to remain in place not only through the weekend but into next week, bringing the coldest air since last Winter. Highs this weekend will range from the single digits and teens in the northern Plains, the 20s/30s in the Midwest, the 30s and 40s for the Northeast, and the 40s and 50s for the South. Morning lows will drop into the 20s for the Northeast, teens in the Midwest, and single digits/below zero for the northern Plains. The worst conditions are expected Saturday morning in the northern Plains and Upper Midwest, where minimum wind chills will fall well below zero. Wind chills across much of the Dakotas and Minnesota will be below negative 15 with portions of North Dakota as cold as negative 30-40. This will pose an increased risk of hypothermia and frostbite on exposed skin. While not quite as dangerous, wind chills will also still be bitterly cold across the Midwest and the Northeast Saturday with breezy winds expected. Another concern will be further south where subfreezing morning lows are forecast this weekend along the southeastern Atlantic coast and west along inland areas of the Gulf Coast, with the possibility of a Frost along the Gulf Coast and into north Florida. Widespread Freeze Warnings are in effect as these temperatures can kill crops and other sensitive vegetation as well as damage unprotected outdoor plumbing. In addition to the cold, heavy, prolonged lake effect snow bands will continue into the weekend for favorable downwind locations across the Great Lakes, including the UP of Michigan, western Michigan, northeastern Ohio, northwestern Pennsylvanian, and portions of upstate New York. Accumulations will measure in feet in the hardest hit areas, with breezy conditions leading to drifting snow as well. Travel will be difficult to impossible, especially for major interstates I-90 between Cleveland and Buffalo and I-81 north of Syracuse. A quick moving upper-level shortwave will also help to trigger some snow showers along and to the north of a frontal boundary stretching across the Middle Mississippi Valley Saturday, the Ohio Valley Saturday night, and into the central Appalachians by Sunday morning. Any accumulations should be light but the quick moving showers may cause some travel troubles for those on the road this weekend. Elsewhere, some showers and thunderstorms will be possible this weekend for South Florida and southern Texas. Conditions across the western half of the country should be mostly dry with temperatures generally at or above average. Forecast highs on Saturday and Sunday range from the 30s and 40s in the northern/central Rockies and Great Basin, 50s for the Pacific Northwest and southern Rockies, 60s for California and Texas, and 70s for the Desert Southwest. Putnam Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php